(a) Field of the Invention
This invention relates to 1-methyl-5-nitro-2-(2-phenylvinyl)imidazoles, useful as antibacterial and anti-protozoal agents.
(b) Description of the Prior Art
German patent application No. 2,035,905 discloses, inter alia, 1-(1-methyl-5-nitro-2-imidazolyl)-2-(4-cyanophenyl)ethylene and 1-(1-methyl-5-nitro-2-imidazolyl)-2-(4-carboxyphenyl)ethylene. Although the patent disclosure speaks of various known 1,2-disubstituted-5-nitro-imidazoles having bactericidal and fungicidal activities, no utility for the compounds that are the subject of the application is given.
Ross et al., J. Med. Chem. 15, 1035-1040 (1972) disclose a series of "2-styryl-5-nitroimidazoles" substituted on the 1-position by ethyl, vinyl or 2-hydroxyethyl, and wherein the phenyl ring of the styryl moiety is either unsubstituted or is substituted by lower-alkyl, chlorine, cycloalkyl, phenyl or methoxy. The compounds were studied for their potential anti-parasitic properties, and the authors concluded that the structural features essential for the desired activity were: "(1) The benzene ring should be substituted by a small 4-alkyl group which itself should carry a hydrogen atom on the .alpha.-carbon atom. (2) The linkage between the nitroimidazole and the aryl function should be olefinic. (3) The nitroimidazole should carry an N-vinyl substituent."
In a further publication of their research on 5-nitro-1-vinyl-2-styrylimidazoles at J. Med. Chem. 16, 347 (1973), the same authors reported the preparation of additional species of the class wherein the phenyl ring of the styryl moiety is substituted by various "unsaturated" functional groups, such as formyl, carboxy, cyano, carboxylic ester or carbamyl groups. The 1-vinyl substituted compounds, which became the primary focus of the Ross et al. work, have the disadvantage that the vinyl group cannot be directly introduced into the molecule but must be generated by chemical manipulations of other groups.
Sarett U.S. Pat. No. 3,487,087 discloses compounds having the formula: ##STR1## "where Ar is aryl; r.sub.1 is . . . lower-alkyl . . . r.sub.2 is hydrogen, . . . r.sub.3 represents hydrogen . . . carboxy, . . . cyano, carboxamido, . . . amidino, . . . lower-alkoxycarbonyl; and r.sub.4 and r.sub.5 are hydrogen or nitro, provided that one and only one of r.sub.4 and r.sub.5 is nitro."
The compounds are stated to be useful as antiprotozoals, particularly against histomoniasis and trichomoniasis.
Miller U.S. Pat. No. 3,549,626 discloses compounds asserted to be "useful as intermediates in the preparation of substituted imidazoles having anti-trichomonal, anti-histomonal, anti-bacterial and anti-parasitic activity" having the formula: ##STR2## "wherein R is lower-alkyl and R' is phenyl, halophenyl, lower alkylphenyl and lower alkoxyphenyl."